/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/OnlineSubsystemUtils.h
Determine if the subsystem module for a given interface is already loaded. Note that modules do not typically initialize the subsystem when the module is loaded.
true if module for the subsystem is loaded
namespace Online { static bool Online::IsLoaded ( const [UWorld](API\Runtime\Engine\Engine\UWorld) * World, const [FName](API\Runtime\Core\UObject\FName) & SubsystemName ) }